
Samsung Galaxy Core Plus
The latest firmware for Samsung Galaxy Core Plus (SM-G350) is G350XXUAPG1 with Android 4.2.2 (Jelly), released on July 3, 2016 for 5 regions (CSC). Every official firmware build for SM-G350, newest first: one row per build with all regions (CSC) that received it.
Each firmware build has its own page at https://samfirm.shop/build/{PDA}, where {PDA} is the build number from the list above. Example: https://samfirm.shop/build/G350XXUAPG1
All 17 builds in our database run Android 4.2.2 (Jelly). The newest build, G350XXUAPG1, was released on July 3, 2016. No new build has appeared for 125 months, so regular updates for this model have most likely ended.
Box codes of SM-G350 for different colors and markets. Firmware is chosen by the model code SM-G350 and your region (CSC), not by the SKU.

SM-G3509

SM-G3589W

SM-G357M

SM-G3568V

SM-G355M
The newest firmware for SM-G350 runs Android 4.2.2 (Jelly): build G350XXUAPG1, released on July 3, 2016.
The latest build for SM-G350, G350XXUAPG1, was released on July 3, 2016 (10 years ago).
SM-G350 has had no new firmware for 125 months, so regular updates have most likely ended.
Yes, all firmware files for SM-G350 are 100% official, original, and obtained directly from Samsung servers.
To flash SM-G350, you need to download the appropriate firmware, put your device into Download Mode, and use the Odin tool to load the BL, AP, CP, and CSC files.
Downgrading is only possible if the bootloader version (binary bit) of the old firmware matches the current one. Always check the binary version before flashing SM-G350.